Low mass density surgical implant and methods of use

ABSTRACT

A surgical implant adapted to treat a prolapse in a patient is provided. The implant comprises a knitted mesh having a mass density of less than 25 g/m 2 . The knitted mesh includes at least one biocompatible polypropylene filament and openings. The implant is configured to be implanted in a region of the prolapse, wherein the prolapse is selected from the group consisting of urethrocoele prolapse, cystocoele prolapse, vault prolapse, uterine prolapse, enterocoele prolapse, and rectocoele prolapse. Methods of using a surgical implant are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application No.13/316,507, filed on Dec. 11, 2011, which is a continuation of U.S.patent application No. 12/551,676, that has issued as U.S. Pat. No.8,100,924 and was filed on Sep. 1, 2009, which is a continuation of U.S.patent application No. 10/473,825, that has issued as U.S. Pat. No.7,594,921 and was filed on Apr. 2, 2002 in the U.S. and, which is theU.S. national phase of International Patent Application No.PCT/GB02/01234, filed Apr. 2, 2002, which claims priority to and thebenefit of Great Britain Patent Application No. 0108088.6, filed Mar.30, 2001, the contents of each application being incorporated byreference herein.

The present invention relates to the treatment of a hernia such as auterovaginal prolapse and, in particular, to a surgical implant for usein such treatment and to a related surgical procedure and device.

A hernia is basically a defect resulting in the protrusion of part of anorgan through the wall of a bodily cavity within which it is normallycontained. For example, a fairly common and well known type of hernia isa defect in the lower abdominal wall resulting in a sac which maycontain a portion of the intestine protruding through the abdominalwall. This is referred to as an inguinal hernia. Similarly, a defect inthe abdominal wall after surgery is referred to as an incisional hernia.Another type of hernia is a defect in the pelvic floor or othersupporting structures resulting in a portion of the uterus, bladder,bowel or other surrounding tissue protruding through, e.g., the vaginalwall. This is usually referred to as uterovaginal prolapse.

A common way of treating hernias is to repair the defect by sutures,whether or not the hernial sac is also sutured or repaired, in orderthat the protruding organ is contained in its normal position. As thedefect generally comprises a weakening and attenuation leading toparting of tissues in a fascial wall, it is usually necessary to applytension to the sutures in order to close the parted tissues. Thus, thefascial wall is generally pinched or tensioned around the area of thedefect in order to close the parted tissues.

This treatment is generally effective, but does have some inherentproblems. In particular, the pinching or tensioning of tissue around thedefect can lead to discomfort and/or recurrence of the hernia.Additionally, in the case of uterovaginal prolapse, such pinching ortensioning of the vaginal wall almost inevitably results in anatomicaldistortion (such as narrowing of the vaginal cavity) with consequentialpain and quality of life implications for the patient and relativelyhigh recurrence and/or complication rates.

In order to address these problems, in the case of inguinal herniarepair, it has been suggested to make use of a surgical implant tooverlay or close the weakened and parted tissues without the need topinch or tension the surrounding tissue of the fascia. Such surgicalimplants generally comprise meshes and are now widely used in inguinalhernia repair. Meshes may be applied subcutaneously (i.e. under theskin), internally or externally of the abdominal wall and may be eitherabsorbable or non-absorbable depending on the nature and severity of theparticular defect being treated. Meshes may be applied in combinationwith sutures to hold the mesh in place or, alternatively, with suturesthat close the parted tissues as in a “non-mesh” technique. Meshes areusually applied in open surgical procedures, although they may sometimesbe applied in laparoscopic surgical procedures.

A typical mesh for an inguinal hernia repair comprises woven or knittedpolypropylene such as Marlex® or Prolene®. Such meshes have a number ofdesirable properties that make them effective for use in hernia repair.For example, they are made of materials that are suitably inert so as tobe less likely to cause adverse reactions when implanted in the body.Furthermore, they are mechanically strong, cheap, easily sterilisableand easy to work with.

However, conventional meshes have a number of inherent problems. Forexample, fistula or sinus (i.e. abnormal passages between internalorgans or between an internal organ and the body surface) can develop asa result of a mesh being implanted and left inside the body. Moregenerally, the placement of a foreign body subcutaneously can also leadto inflammation or infection. Similarly, edge extrusion (i.e. theerosion of body tissue around the edge of the mesh) can occur.Nevertheless, overall, the use of meshes is generally considered to bebeneficial in the treatment of incisional and inguinal hernias.

It has also been suggested to use meshes in the treatment ofuterovaginal prolapse. Meshes that have been proposed for use in therepair of uterovaginal prolapse are similar to those that are used forthe repair of inguinal hernia and such like. However, there is concernthat the above mentioned problems with the use of meshes are greaterwhen a mesh is placed in the vaginal wall as this tissue is generallythin only just below the surface and therefore more prone to adversereactions. Furthermore, the placement of a foreign body close to therectum and urinary tract may increase the risk of infection,inflammation, erosion, fistula or translocation. Thus, it is arelatively widespread view that the use of meshes in the treatment ofvaginal prolapse is less desirable than in the treatment of otherhernias.

Nevertheless, as the use of meshes to treat uterovaginal prolapse canavoid anatomical distortion and the above mentioned problems related tothis, the Applicant considers there are significant benefits in the useof meshes in the treatment of uterovaginal prolapse should it bepossible to mitigate the problems associated with mesh treatment.

The applicant has recognised that there are a number of specificfeatures of conventional meshes that exacerbate the problems of fistula,sinus, edge extrusion, infection etc., particularly when these meshesare implanted in the vaginal wall. The Applicant has therefore realisedthat it is possible to provide a surgical implant that has the benefitsof mesh treatment, i.e. the avoidance of anatomical distortion and itsrelated problems, and also minimises the above mentioned problems.

One specific problem with conventional meshes that the Applicant hasrecognised is that they have jagged or rough edges. The rough edgesarise as conventional meshes are generally formed from sheets ofmultiple woven or intersecting fibres or strands. When the meshes arecut to size in manufacture or prior to fitting, the stray ends of thefibres or strands are left extending from the edge of the mesh,particularly where the edge is curved. In other words, the perimeter ofthe mesh comprises the spaced ends of the fibres or strands and is notsmooth. It is thought that the jagged rough nature of the edges of theimplant increases the likelihood of extrusion of the edge of the mesh insitu.

Conventional meshes are generally unnecessarily strong and substantialfor use in the vaginal wall and of significant mass. This results in anunnecessary excess of foreign body material in the vaginal wall,increasing the risks associated with the placement of foreign bodiesinside the human body, such as the risk of infection. Likewise, the bulkof such meshes can undesirably result in discomfort for the patient asthe mesh can often be felt when in position. This is of particularconcern when a mesh is placed in sensitive vaginal tissues or near tobowel or bladder.

A further disadvantage of the meshes presently used to treat herniasrelates to pore size. The pore size of meshes in use is unphysiologicaland does not encourage acceptance of the implant in the body.

It is a aim of the present invention to overcome problems associatedwith existing meshes used to treat hernias.

According to the present invention there is provided a surgical implantsuitable for treatment of hernias, the implant comprising a mesh havinga residual maximum mass density of 50 g/m².

Preferably the maximum mass density is less than 30 g/m². Morepreferably the maximum mass density is less than 25 g/m².

By minimising mass density of a mesh for use in treating hernias theadvantages of using a mesh are still apparant whereas the disadvantagesare lessened in that jagged and rough edges are minimised as is the riskof infection. The residual mass density is the mass density of the meshafter implantation.

Preferably the surgical implant mesh comprises strands and includesmajor spaces and pores.

The strands of the mesh may be formed by at least two filaments, themajor spaces formed between the strands providing the surgical implantwith the necessary strength, the filaments arranged such that pores areformed in the strands of the mesh.

Alternatively the strands may be formed by monofilaments which formloops which give rise to the pores.

Preferably strands are spaced by wider distance than the fibres orfilaments of conventional meshes used in hernia repair.

Preferably the strands are spaced apart to form major spaces of between1 to 10 mm.

More preferably the strands are spaced apart to form major spaces ofbetween 2 to 8 mm.

The use of mesh having strands spaced between 1 to 10 mm apart has theadvantage of reducing the foreign body mass that is implanted in thehuman body. Only sufficient tensile strength to securely support thedefect and tissue being repaired is provided by the mesh.

It is desirable that the mesh of the present invention has a mass ofbetween one tenth ( 1/10th) and one hundredth ( 1/100th) that of aconventional, e.g. Prolene®, mesh of the same surface area. The mesh ofthe invention therefore avoids the unnecessary bulk of conventionalmeshes.

More specifically it is preferred that the mass density is less than 50g/m², more preferably less than 30 g/m and most preferably less than 20g/m². It is also preferred that the strands of the mesh of the presentinvention are narrower than those of meshes of the prior art.

Preferably the strands have a diameter of less than 600 μm.

In one embodiment the strands are arranged to form a diamond net mesh.

In an alternative embodiment the strands are arranged to form ahexagonal net mesh.

The strands and filaments are preferably warp knit.

In an alternative embodiment the strands are arranged to form a net meshwith suitable tensile strength and elasticity.

Preferably the strands are arranged to form a net mesh which hasisotropic or near isotropic tensile strength and elasticity.

Preferably the filaments have a diameter of between 0.02 to 0.15 mm.

More preferably the filament of the mesh is of a diameter 0.08 to 0.1mm.

This likewise has the advantage of reducing the overall bulk of theimplant, and hence the amount of material retained in the human body.

Particular meshes which are embodiments of the present invention includewarp knit diamond or hexagon net diamond net meshes. Four particular.embodiments are set out below.

In two particular embodiments wherein the filaments are formed frompolypropylene having a diameter of 0.07-0.08 mm wherein the strands arespaced to form spaces of either 2 mm or 5 mm.

Alternatively, filaments are formed from polyester having a diameter of0.09 mm wherein the strands are spaced to form spaces of 5 mm.

Alternatively, filaments are formed from polyester having a diameter of0.05-0.07 mm wherein the strands are spaced to form spaces of 2 mm.

As the surgical implant is comprised of narrow members arranged to bespaced by relatively wide gaps, major spaces, tissue may be slow to growinto the mesh. It is desirable for the mesh to have means for promotingtissue ingrowth. More specifically, it is desirable to provide pores inthe strands of the mesh to aid tissue ingrowth and to which tissue maymore easily adhere.

Preferably two filaments are interwoven/knitted to produce strands ofthe mesh comprising pores.

Alternatively at least three filaments are interwoven/knitted to producestrands of the mesh comprising pores.

For manufacturing reasons it is preferred that two filaments are used toform the pores in the strands of the mesh which aid tissue ingrowth,however if the one filament could be suitably knotted or twisted to formpores of suitable dimensions it is clear that this could be used tosimilar effect to form the strands of the mesh.

Preferably the pores in the strands are of between 50 to 200 μm indiameter.

More preferably the pores are of between 50 to 75 μm in diameter.

This is important in enabling efficient fibroblast throughgrowth andordered collagen laydown in order to provide optimal integration intothe body. This is discussed in detail in copending Patent ApplicationNo. PCT/GB01/04554.

Rings or loops of material comprising pores of between 50 to 200 μm maybe adhered to or formed on the strands of the mesh to provide pores.

As mentioned above, reducing the mass of the mesh has distinctadvantages in relation to the suitability of the mesh for implantationin the body, i.e. the reduction of foreign body mass and improving thecomfort of the patient. However, the handling characteristics of such amesh, e.g. the ease with which a surgeon can manipulate and place thesurgical implant in its desired location in the body, can be poor insome circumstances. More specifically, a mesh having narrow members orstrands that are widely spaced will inevitably be somewhat flimsy andlacking in rigidity compared to conventional meshes.

Ideally the implant should be formed from materials or uses technologieswhich provide the implant with Dual Phase Technology™, such that it hassuitable surgical handling characteristics and is also of minimal massand suited for implantation in the body. The implant may be formed froma range of materials to provide it with Dual Phase Technology™.

The term Dual Phase Technology™ refers to a means to provide temporarysubstance to the mesh. Depending on the type of Dual Phase Technology™employed the benefits imported, in addition to allowing minimal residualmesh mass may include assisting the mesh to be handled and cut,minimizing the effect of rough edges, assisting placing the mesh inposition and providing tackiness to assist in holding the mesh inposition on implantation, thus minimising or negating the need for anyadditional fixation by suturing or adhesion.

In a preferred embodiment of the invention having improved handlingcharacteristics, the implant therefore has an absorbable coating.Preferably this coating encapsulates the mesh of the surgical implant.

Alternatively this coating is applied to at least one face of the mesh.

The coating, covering or layer of absorbable material stiffens and addsbulk to the mesh such that it is easier to handle.

As the coating, covering or layer is absorbable, it is absorbed by thebody after implantation and does not contribute to the foreign body massretained in the body. Thus, the advantages of a surgical implant havingminimal mass are retained.

Preferably the coating, covering a layer absorbs within 48 hoursfollowing implantation.

The coating, covering or layer may comprise any suitable soluble andbiocompatible material.

Suitable hydrogel materials can be obtained from First Water in the UK.A typical hydrogel being developed for use in this application is knownas FIRST PHASE™ or PHASE1™.

The absorbable material may be a soluble hydrogel such as gelatin,

Alternatively the absorbable material is a starch or cellulose basedhydrogel.

In a further alternative the absorbable material is an alginate.

In a further alternative the absorbable material may contain hyaluronicacid.

The coating, covering or layer may have any thickness or bulk thatprovides the surgical implant with suitable handling characteristics.

Preferably, the coating is a sheet with a thickness greater than that ofthe mesh.

Suitable handling characteristics may also be provided to the mesh by arange of other methods. The surgical implant may comprise a mesh and abacking strip the backing strip releasably attachable to the mesh.

The backing strip may be formed from a range of materials includingplastics.

The surgical implant may be releasably attachable to the backing stripby adhesive.

The releasable attachment of a backing strip to the mesh provides a moresubstantial and less flexible surgical implant that is more easilyhandled by a surgeon. Following suitable placement of the surgicalimplant the backing strip can be removed from the surgical implant, thesurgical implant being retained in the body and the backing materialbeing removed by the surgeon. The surgical implant can therefore benefitfrom reduced mass while still providing characteristics required forsurgical handling.

In a further alternative the strands of the mesh of the surgical implantare comprised of bicomponent microfibres.

Preferably the bicomponent microfibres comprise a core material andsurface material.

The composite or biocomponent fibres preferably comprise a nonabsorbableor long lasting absorbable core and a shorter lasting absorbable surfacematerial.

Whereas any licenced materials may be used, suitable materials presentlyavailable include polypropylene for the core and polylactic acid orpolyglycolic acid for the surface materials.

Alternatively the bicomponent microfibres comprise an material which israpidly absorbed by the body and a material which is not absorbed for asuitable longer period of time.

Preferably the surface material is capable of being absorbed by the bodyin a period of less than 48 hours.

Preferably the core material is capable of remaining in the body for aperiod of time sufficient to enable tissue ingrowth.

The surface material of the bicomponent microfibres or a portion of thecomposite polymers present during the insertion and placement of thesurgical implant provides the surgical implant with characteristicsrequired for surgical handling.

Following a period of insertion in the body, the surface material of thebicomponent microfibre is absorbed by the body leaving behind thereduced foreign mass of the core material of the strands of the mesh.

It is preferred that the surface material of the bicomponent microfibreis absorbed by the body within a number of hours such that only a coreportion is left in the body for an extended length of time. Typicallymaterials presently available which could be used to form themicrofibres are absorbed by the body over a period of days or weeks.

The filaments of the mesh comprise a plastics or synthetic material.

Preferably the filaments of the mesh comprise of polypropylene orpolyester.

Alternatively the filaments of the mesh comprise an absorbable material.

It can be appreciated that filaments which comprise in part ofabsorbable material would allow better surgical handling, but wouldenable the implant to also have minimal mass following implantation inthe body.

Preferably the surgical implant comprises material that has memory.

Preferably the surgical implant has memory which urges the surgicalimplant to adopts a flat conformation.

Preferably the implant has a generally curved perimeter, i.e. to havefew or no corners or apexes, as sharp corners increase the likelihood ofedge erosion and infection. The specific shape will, however, varyaccording to the use to which the implant is to be put.

Due to the variety of sizes of such defects, and of the various fasciathat may need repair by the implant, the implant may have any suitablesize,

Preferably the surgical implant is of width between 1 cm to 10 cm and oflength between 1 cm to 10 cm.

It may be desirable to provide a variety of implants having differentsizes in order that a surgeon can select an implant of suitable size totreat a particular patient. This allows implants to be completely formedbefore delivery, ensuring, for example, that the smooth edge is properlyformed under the control of the manufacturer. The surgeon would have avariety of differently sized (and/or shaped) implants to hand and selectthe appropriate implant to use after assessment of the patient.

Typically an anterior uterovaginal prolapse is ellipse shaped or atruncated ellipse whereas a posterior prolapse is circular or ovoid inshape.

Accordingly the implant shape may be any one of elliptical or tuncatedellipse, round, circular, oval, ovoid or some similar shape to be useddepending on the hernia or polapse to be treated.

Different shapes are suitable for repairing different defects in fascialtissue and thus by providing a surgical implant which can be cut to arange of shapes a wide range of defects in fascial tissue can betreated.

Preferably the mesh can be cut to any desired size. The cutting may becarried out by a surgeon or nurse under sterile conditions such that thesurgeon need not have many differently sized implants to hand, but cansimply cut a mesh to the desired size of the implant after assessment ofthe patient. In other words, the implant may be supplied in a large sizeand be capable of being cut to a smaller size, as desired.

In this regard, whilst the surgical implant of the invention isparticularly useful for the repair of uterovaginal prolapse, it may beused in a variety of surgical procedures including the repair ofhernias.

Preferably the surgical implant is suitable for use in the treatment ofhernias including incisional and inguinal hernias and/or for thetreatment of uterovaginal prolapse.

More broadly, the Applicant has therefore recognised that the implantcan have any shape that conforms with an anatomical surface of the humanor animal body that may be subject to a defect to be repaired by theimplant.

As discussed a disadvantage of the meshes used in hernia repair is thatthey have jagged or rough edges. Due to the wide spacing between strandsof the mesh described above and the small diameter of the filaments, theedge problems are mitigated to an extent by the present invention.

To further reduce edge problems it would be preferable if a mesh had acircumferential member which extends, in use, along at least part of theperimeter of the implant to provide a substantially smooth edge.

In other words, the mesh has at least one circumferential member (i.e.fibre, strand or such like) that extends around at least part of itscircumference.

Preferably at least part of the perimeter of the implant is defined bythe circumferential member.

Alternatively at least part of the perimeter of the implant is definedby more than one circumferential member, at the edge of the mesh.

The edge of the mesh, and hence the perimeter of the implant, cantherefore be generally smooth and this has significant advantages overconventional surgical meshes. Specifically, the Applicant has recognisedthat an implant having a smooth edge is less likely to cause edgeextrusion or erosion.

Any amount of the perimeter of the implant may be defined by thecircumferential member(s).

However, in order to maximise the benefits of the implant of theinvention, it is preferable that at least 50% of the perimeter of theimplant is defined by the circumferential member(s).

More preferably at least 80% of the perimeter of the implant is definedby the circumferential member(s).

Most preferably 100% of the perimeter of the implant is defined by thecircumferential member(s).

The majority or the whole of the perimeter of the mesh being smoothminimises the risk of a rough edge causing edge erosion or infection.

The circumferential member(s) may be arranged in one of a variety ofways to provide the smooth edge or perimeter.

Preferably the circumferential members are arranged such that they eachfollow the edge of a desired shape of the surgical implant, theperimeter of the implant formed from as few members as possible.

This simplifies the construction of the mesh, which is desirable notonly for manufacture, but also because simpler structures are lesslikely to have defects which might be problematic after implantation.

Preferably the perimeter of the mesh is defined, in use, by onecircumferential member.

Preferably the mesh has a plurality of circumferential members arrangedat different radial locations.

In order to provide an implant of given dimensions, the periphery of themesh outward of the desired circumferential member is cut away such thatone or more selected circumferential members form the perimeter of theimplant as desired.

More preferably, the circumferential members are arrangedconcentrically.

A concentric arrangement of a plurailty of circumferential membersconveniently allows maintenance of the shape of the implant fordifferent sizes of implant and provides the mesh with an even structure.

The remainder of the structure of the mesh may take a variety of forms.

The circumferential members can be arranged to join with one another inorder to form an integral mesh.

Alternatively the mesh may additionally comprise transverse memberswhich extend across the circumferential members joining thecircumferential members.

The transverse members may extend radially from a central point to theperimeter of the implant.

Alternatively, the transverse members may extend toward the perimeter ofthe implant.

Preferably the transverse members are arranged to provide substantiallyeven structural strength and rigidity to the implant.

It may be desirable to secure the mesh in place once it has beensuitably located in the patient.

Preferably the mesh can be sutured to strong lateral tissue.

Alternatively, the mesh may be glued in place using a biocompatibleglue.

This is advantageous, as it is fairly quick to apply glue to the areaaround the surgical implant.

Preferably the mesh comprises at least one capsule containingbiocompatible glue for securing the implant in place.

Preferably 4 capsules containing glue are provided around the perimeterof the surgical implant.

Preferably the capsules comprise hollow thin walled spheres of around 3to 5 mm diameter including gelatin.

Preferably the glue is a cyanoacrylate glue.

Conventionally, open procedures have been preferred for the treatment ofhernias with meshes, as relatively broad access is required to the siteof the defect to suitably implant and secure a mesh by sutures or suchlike.

However, it is desirable to treat hernias, as when carrying out anysurgery, with as little trauma to the patient as possible. Thus, the useof minimally invasive techniques has been suggested for the treatment ofhernias. However, such surgical techniques have not been considered tobe useful in the treatment of uterovaginal prolapse with a mesh, as ithas not been considered practical to position a mesh subcutaneously inthe vaginal wall due to the difficulty in gaining direct access to thisarea.

According to another aspect of the present invention, there is provideda minimally invasive method of treating uterovaginal prolapse, themethod comprising the steps;

making an incision in the vaginal wall close to the opening of thevaginal cavity and,

making a subcutaneous cut, through the incision, over and surroundingthe area of the prolapse, which cut is substantially parallel to thevaginal wall; and

inserting a mesh according to the present invention, through theincision, into the space defined by the cut.

Thus, a mesh or the surgical implant such as that according to theinvention can be inserted through a small incision (e.g. around 1 cm to2 cm in length) at or in the region of the periphery or opening of thevaginal cavity. An incision in this position is easier for a surgeon toaccess than an incision deeper in the vaginal cavity, yet the Applicanthas realised that it is also convenient to treat vaginal prolapse byimplanting a mesh in a surgical procedure carried out entirely throughsuch an incision.

Preferably, the incision is at the anterior or posterior extremity ofthe prolapse sac of the vaginal cavity.

This is desirable as prolapse most often occurs in the anterior orposterior vaginal wall, so positioning the incision in such a locationallows the most convenient access to these parts of the vaginal wall.

The provision of suitable handling characteristics for the mesh isparticularly advantageous when the mesh is intended to be used in aconventional open surgical procedure, as the surgeon needs to handle theimplant directly in order to place it in its desired location.

However, the suitable placement particularly in the treatment ofuterovaginal prolapse, by minimally invasive techniques require the meshto be as flexible as possible and therefore to have no absorbablecoating or encasement.

A flexible, less bulky mesh may be more easily handled by tools that maybe used to carry out the procedure.

Tools that may be used to carry out this procedure have a number ofspecific needs that need to be met that are not presently met byconventional minimally invasive surgical tools.

These specific needs can best be understood by considering the steps ofthe surgical procedure of the invention in turn.

The incision is made in the vaginal wall at the opening of the vaginalcavity. This can be carried out using a conventional implement such as ascalpel. It is preferable that the incision is as small as possible asthis reduces trauma to the patient.

A cut is then made in the vaginal wall over the defect causing theprolapse or hernia. For example, scissors or another specialised cuttingtool can be inserted through the incision and manipulated to provide acut over the defect. The cut is below the surface of the skin and mayprovide a space between an upper (or outer) layer and a lower (or inner)layer of the vaginal wall, or between the skin and the vaginal wall, inthe region of the defect, into which cavity the mesh can be inserted.

Next, the mesh is placed in the space defined by the cut. It ispreferred that the mesh of the invention is supplied rolled up in orderthat it can be inserted through a small incision and unfurled in situ,i.e. in its intended position. Thus, it may be possible for the surgeonto insert the mesh through the incision by hand. However, this is likelyto result in the incision needing to be large enough for the surgeon toinsert a finger to manipulate the mesh in the space. This may causeunnecessary trauma to the patient and can be difficult for a surgeon tocarry out.

According to another aspect of the present invention, there is provideda surgical tool for delivering a mesh subcutaneously through anincision, the tool being adapted to radially confine the mesh duringdelivery and being operable to release the mesh in its intendedposition.

Such a tool for placement of a mesh or the surgical implant of thepresent invention can insert and position the mesh or surgical implantin a convenient and controlled manner through a small incision.Furthermore, the incision through which the mesh is inserted need onlybe as large as the diameter of the tool, or the tool when carrying themesh, which can be significantly smaller than where a surgeon's fingermust be able to fit through the incision.

Preferably the tool comprises a housing and unfurling means the housingand unfurling means insertable through an incision in the patient, thehousing and unfurling means adapted to accommodate a rolled up mesh andseparable to release the mesh the unfurling means capable of unfurlingthe rolled up mesh without any significant movement around the area ofthe incision

Preferably, the tool comprises two or more parts, the parts movable suchthat in a first position they house the mesh or surgical implant and, ina second position the mesh or surgical implant is released. Morepreferably the tool comprises two semi-circular channels, an innerchannel having an external diameter suitable for fitting inside an outerchannel.

The channels may be rotatable about a common axis such that in a firstposition the open faces of the channels face one another to form aclosed housing and in a second position the inner channel sits insidethe other channel to release the mesh.

Alternative the tool comprises a shaft and releasable securing means,the shaft adapted such that the mesh can be rolled around the shaft andreleasable securing means to secure the rolled mesh in place.

In use, the tool is inserted through the incision with the mesh rolledaround the outside of the shaft. Once the tool has been inserted, themesh is released by turning the shaft to unroll the mesh at the sametime as moving the shaft across the space in which the mesh is beingplaced.

A needle may be used to secure the free, outer end of the mesh whilst itis unfurled. The needle may be inserted through the vaginal wall to pinthe mesh in place. Similarly, where the mesh is released from within ahousing, needles may be used to ease the mesh out of the open housing.

In an alternate embodiment, the tool comprises two or more arms, each ofwhich is releasably attached at one end to an edge of the surgicalimplant. The arms may be movable from a first position in which theyradially confine the mesh to a second position to unfurl the mesh in itsintended position.

In one example, the arms are pivotally interconnected such that they canbe manipulated to move the ends of the arms from the first position tothe second position.

In another example the arms may be arranged to extend radially outwardfrom a housing to move from the first position to the second position.The extendable arms may comprise wires arranged to be extendable andretractable from and into the housing by operation at an end of thehousing.

In another example, the arms may be resilient or sprung elements thatcan be released from the first position and move into the secondposition to which they are biased, i.e. to unfurl the mesh.

As can be appreciated, all of the above, embodiments of the tool areable to unfurl the mesh without any significant movement around area ofthe incision. For example, the pivot can be arranged to coincide withthe incision, the tool rolled around an arc centred at the incision orthe arms operated or housing opened forward of the incision. Thus, theincision can be small as no lateral movement is required at the area ofthe incision.

Embodiments of the present invention will now be described, by way ofexample only, with reference to the accompanying drawings, in which:

FIG. 1 is an illustration of a hernia;

FIG. 2 is an illustration of the hernia of FIG. 1 when intra-abdominalpressure is raised;

FIG. 3 is an illustration of the hernia of FIG. 1 after repair inaccordance with the prior art;

FIG. 4 is an illustration of the hernia of FIG. 1 after an alternaterepair in accordance with the prior art;

FIG. 5 is a schematic illustration of the female human vaginal area;

FIG. 6 is a cross-sectional view of the female human vaginal area alongthe line A-A of FIG. 5;

FIGS. 7 a and 7 b illustrate surgical implants according to theinvention having a first shape;

FIGS. 8 a, 8 b, 8 c and 8 d illustrate surgical implants according tothe invention having a second shape;

FIGS. 9 a, 9 b 9 c and 9 d illustrate surgical implants according to theinvention having a third shape;

FIG. 10 illustrates a first surgical tool according to the invention incross-section;

FIG. 11 illustrates a second surgical tool according to the invention;

FIG. 12 illustrates a third surgical tool according to the invention;and

FIG. 13 illustrates a fourth surgical tool according to the invention.

Referring to FIGS. 1 and 2, a hernia, vaginal prolapse or such likeoccurs when a fascial wall 1 ruptures, forming a defect 2, i.e. aweakening or, in this case, parting of the fascial wall 1. An organ 3,contained by the fascial wall 1 is then able to protrude through thedefect 2. Such protrusion is illustrated in FIG. 2 and occursparticularly when pressure within the cavity defined by the fascial wall1 is raised. For example, in the case of an inguinal hernia, when apatient coughs, intra-abdominal pressure is raised and the intestinesmay be pushed through the defect 2 in the abdominal wall.

Whilst the organ 3 that may protrude through the defect 2 is usuallystill contained by some other membrane 4, the hernia, prolapse or suchlike is inevitably painful and liable to infection or othercomplications. An effective and desirable treatment is therefore toclose the defect 2 and contain the organ 3 in its normal position.

Referring to FIG. 3, hernias, vaginal prolapse and such like areconventionally repaired by providing sutures 5 across the defect 2 tojoin the tissues of the fascial wall 1. In addition, it may be firstlynecessary to plicate (i.e. fold or reduce) the membrane 4 as this mayhave stretched due to distention of the organ 3. Plication of themembrane 4 corrects the stretching and helps to relieve pressure on thearea of the defect 2 during healing as the membrane 4 can act to containthe organ 3 to some extent. Plication is generally achieved by applyingsutures 6 to the membrane 4.

Referring to FIG. 4, it is also a known method of treating hernias toprovide, additionally or alternatively to sutures, a mesh 7 across thedefect 4. This allows for the defect 2 to be repaired without the partedtissues of the fascial wall 1 necessarily being brought together and forthe defect to heal without the fascial wall 1 being pinched or tensionedto correct the defect 2.

FIG. 5 schematically illustrates (a sagittal view of) the female humanvaginal area. The vagina 8 is illustrated with its anterior portion(front) at the top of the diagram and the posterior portion (rear) atthe bottom of the diagram. The opening of the urethra, or urethralmeatus, 9 is at the forward or anterior end of the vagina 8. The centralportion of the vagina 8 forms the vaginal cavity which terminates at thecervix 10. Spaced from the rearward or posterior end of the vagina 8 isthe anus 11. Four areas A to D of the vaginal wall 12 are outlined inFIG. 5. These areas A to D are those areas of the vaginal wall 12 inwhich vaginal prolapse often occurs.

Referring to FIG. 6, which is a cross sectional view along the line A-Ain FIG. 5, it can be more clearly seen that the wall 12 of the vagina 8is bounded by the bladder 13 and urethra 14, the uterus 15, the smallbowel 16 and rectum 17. The small bowel 16 and rectum 17 are separatedby the “Pouch of Douglas” PoD.

Area A is the lower one third of the anterior vaginal wall 12 (i.e. theone third nearest the entrance to the vaginal cavity) adjacent thebladder 13 and urethra 14. Prolapse in this area is referred to asanterior or, more specifically, urethracoele prolapse. Area B is theupper two thirds of the anterior vaginal wall 12. Prolapse in this areais referred to as anterior or, more specifically; cystocoele prolapse.The central area of the vaginal wall 12 in which the cervix 10 islocated is adjacent the uterus 15 and prolapse in this area is referredto as central, uterine or vault prolapse. Area C is the upper one thirdof the posterior vaginal wall 12. This area of the vaginal wall 12 isadjacent the small bowel 16 and prolapse in this area is referred to asposterior or entreocoele prolapse. Finally, area D is the lower twothirds of the posterior vaginal wall and is adjacent the rectum 17.Prolapse in this area is generally referred to as posterior orrectocoele prolapse.

Conventionally, any of the above types of hernia have been treated byproviding sutures in the area of the prolapse. For example, the extentof the defect causing the prolapse is first identified by the surgeon.Lateral sutures, i.e. sutures from one side to the other of the vaginalwall 12 as seen in FIG. 5 or right to left rather than anterior toposterior, are provided across the area of the defect. This joins theparted tissues of the vaginal wall and repairs the defect. The organprotruding through the vaginal wall is therefore contained.Disadvantages of this technique include anatomical distortion of thevagina due to tensioning of the wall by the sutures to repair thedefect.

A surgical implant for use in the repair of vaginal prolapse inaccordance with an embodiment of the present invention comprises a mesh20. The mesh is comprised of strands 22. The strands being less than 600μm and approximately 150 to 600 μm in diameter. The strands are arrangedsuch that they form a regular network and are spaced apart from eachother such that for a diamond net a space of between 2 mm to 5 mm existsbetween the points where the strands of the mesh interact with eachother (a). In a hexagonal net arrangement the space is between 2 mm to 5mm between opposite diagonal points where the strands of the meshinteract (b).

It is preferable to space the strands as far as part as possible toallow blood to pass through the implant and reduce the mass of theimplant, while providing the mesh with sufficient tensile strength andelasticity to be effective. It can therefore be appreciated thatconsiderable variability in the maximum spacing between the strands canbe achieved depending of the material from with the strands arecomprised and the net pattern in which the strands are arranged.

In the embodiment shown in FIG. 7 a the strands are arranged in adiamond net pattern 24, however any pattern which provides suitabletensile strength an elasticity may be used.

For example a hexagonal net pattern may be used as shown in FIG. 7 b.

Ideally in order to reduce the overall mass of the implant the strands22 should have as narrow a diameter as possible while still providingthe mesh 20 with suitable tensile strength and elasticity.

The strands 22 of the mesh 20 are comprised of at least two filaments 26arranged to interact such that pores 28 are formed between the filaments26.

The pores 28 formed between the filaments 26 are around 50 to 200 μm,such a spacing allowing fibroblast through growth to occur. Thisfibroblast through growth secures the implant 20 in place within thebody. Additionally and importantly the suitably sized pores allow theimplant 20 to act as a scaffold to encourage the lay down of new tissue.The lay down of new tissue promotes the healing of the hernia.

The filaments 26 may be formed from any biocompatible material. In thisembodiment the filaments 26 are formed from polyester, wherein eachpolyester filament 26 is around 0.09 mm in diameter.

In the embodiment shown the filaments 26 of the strands 24 are knittedtogether using warp knit to reduce the possibility of fraying of thefilaments 26 and strands 24.

Alternative suitable materials of which the filaments may be formedinclude polypropylene.

Suitable materials from which the mesh can be made: provide sufficienttensile strength to support a fascial wall during repair of a defect inthe fascial wall causing a hernia; are sufficiently inert to avoidforeign body reactions when retained in the human body for long periodsof time; can be easily sterilised to prevent the introduction ofinfection when the mesh is implanted in the human body; and havesuitably easy handling characteristics for placement in the desiredlocation in the body.

The fine warp knit of the filaments 26 provides a surgical implant whichis flexible in handing, which can be easily cut into different shapesand dimensions. As the strands 24 are formed using warp knit thepossibility of fraying of the edge of the surgical implant 20 followingproduction or cutting of the surgical implant 20 is reduced.

Other methods of reducing fraying of the filaments 24, not arranged toform the strands using warp knit, following cutting or production of theimplant are heat treatment, laser treatment or the like to seal theedges of the surgical implant.

The mesh 20 may be supplied in any shape or size and cut to theappropriate dimensions as required by the surgeon.

It can be appreciated that cutting of the mesh will produce anunfinished edge 30. Due to the sparse nature of the strands that formthe mesh and their narrow diameter this unfinished edge does not sufferfrom the same problems as edges of meshes of the prior art.

In other words the edge produced is not rough and jagged such that itincreases the likelihood of extrusion of the edge of the mesh in situ orthe chance of infection.

As discussed an advantage of the mesh of the present invention is thatit allows the production of a mesh suitable for use in hernia repairwhich allows substantially less foreign material to be left into thebody.

However, the mesh being flexible and insubstantial is less suitable forallowing easy handling of the mesh directly by a surgeon. Referring toFIGS. 8 a and 8 b the mesh described above may be treatable using anabsorbable coating 32.

The absorbable coating 32 comprises a layer of absorbable materialhaving a thickness greater than that of the strands 22 of the mesh 20.For example, the thickness of the layer of absorbable material may bearound 1 to 2 mm. The strands 22 of the mesh 20 may be entirely embeddedin the absorbable coating 32 such that the outer surface of the mesh 20is covered entirely of the absorbable coating 32.

In effect the entire surgical implant is encased in the absorbablecoating as shown in FIG. 8 b.

Thus, the surgical implant has no gaps or holes on its surface. This hasthe advantage of reducing the likelihood of bacteria becoming lodged onthe strands 22 of the mesh 20 before implantation of the mesh 20.Furthermore, the absorbable coating 32 makes the mesh 20 moresubstantial and less flexible such that it is more easily handled by asurgeon. This is particularly useful when it is desired to place themesh in a desired location in a conventional, open surgical procedure.

In an alternative embodiment shown in FIG. 8 a the absorbable coating 32comprises a layer of absorbable material applied to one face 34 of themesh 20, such that the mesh has a first face 34 on which the absorbablematerial has been applied and a second face 36 on which the absorbablematerial has not been applied such that the first and second faces 34and 36 each have different characteristics.

It can also be envisaged that the surgical implant is provided withimproved surgical handling qualities by a range of other methods. Suchmethods including, the releasable attachment of the mesh 20 to a backingstrip 40. This embodiment is shown in FIG. 8 c.

The backing strip may be formed from plastics material and is adhered tothe surgical implant using releasable adhesive.

In a similar fashion to the absorbable coating the backing strip 40causes the mesh 20 to be more substantial and less flexible such that itis more easily handled by a surgeon. Following the suitable placement ofthe mesh 20 the backing strip 40 can be removed from the mesh 20, themesh 20 being retained in the body and the backing material 40 beingremoved by the surgeon. Application of the backing strip 40 to the mesh20 means the mesh 20 benefits from reduced mass but that the mesh 20 andbacking strip 40 together give characteristics required for surgicalhandling.

In a further embodiment the filaments of the mesh may be comprised frombicomponent microfibres 50 or composite polymers 60. These technologiesprovide the implant with dual phase technology.

As shown in FIG. 8 d the bicomponent microfibres 50 comprise a core 52(cutaway section shows core region) and surface material 54. The surfacematerial 54 is designed such that it is absorbed by the body in a matterof hours, while the core material 52 remains in the body for a longerperiod to enable tissue ingrowth.

Suitable bicomponent microfibres 50 include a polypropelene nonabsorable portion and a polylactic acid absorbable portion.

The surface material 54 is present during the surgical procedure whenthe mesh 20 is being inserted and located in the patient, and providesthe mesh with characteristics desirable for surgical handling. Followinga period of insertion in the body, typically a few hours, the surfacematerial 54 is absorbed into the body leaving only the core material 52of the filaments 26 in the body. The core material of the filamenthaving reduced foreign mass in comparison to meshes of the prior art orthe mesh 20 when it also includes the surface material 54.

As shown in FIG. 8 e the mesh of the surgical implant may be formedcomposite polymers 60. As described for the bicomponent microfibres 50,composite polymers 60 provide the surgical implant with dual phasetechnology. A first face 62 of the mesh 20 thus having particularcharacteristics such as flexibility and elasticity, while a second face64 of the mesh 20 provides the mesh 20 with characteristics whichimproved the surgical handling of the mesh 20 such as strength androbustness. The cutting of the mesh described causes an unfinished edgeof the mesh to be produced. This unfinished mesh not being as likely tocause the same problems as the rough and jagged edges of the implants ofthe prior art, due to the fewer strands, smaller diameter filaments andtreatment of the mesh with absorbable coating which protects the tissuefrom the mesh during the surgical procedure when damage is most likelyto occur.

Referring to 9 a, a further embodiment of the mesh may comprise strandsas discussed and more specifically, perimeter strands. Typically themesh is circular or the like in shape and thus this perimeter strand canbe generally referred to as a circumferential strand 70.

In the example shown in FIG. 9 a one strand runs around thecircumference of the oval shape of the mesh 20. In another embodiment,several circumferential strands 70 may be present, each circumferentialstrand 70 may extend over one side of the oval mesh 20, i.e. around halfthe circumference of the mesh.

As shown in FIG. 9 b the circumferential strands 70 are arrangedconcentrically and each extends around the mesh 20 at a different radiallocation.

An outer circumferential strand 70 extending around the perimeter of themesh 20, and further circumferential strands 72 and 74 are arrangedinwardly of the outer circumferential strand forming a perimeter spacedby a distance (a). The distance a between adjacent circumferentialmembers 70, 72 and 74, can vary and in this example is 20 mm.

Transverse strands 76 extend from the centre of the oval mesh 20 topoints on the perimeter of the mesh 78. In this example, four transversestrands 76 are provided across the diameter of the mesh 20, dividing themesh 18 into eight angularly equal portions.

The mesh 20 of this embodiment may be formed from materials aspreviously described. Depending on the material chosen the mesh may bewoven, knitted or extruded as one piece, or individual or groups ofstrands can be extruded separately and joined to one another.

Such a construction as described above provides a mesh 20 withsufficient tensile strength to repair defects causing vaginal prolapsewhilst having minimal bulk. Similarly, such a construction provides asuitably flexible yet resilient mesh for handling using the surgicaltools described below. Referring to FIGS. 9 c and 9 d, meshes 80, 82 ofin the shape of the outline having angled sides respectively, ratherthan oval, are illustrated.

These meshes have a similar structure to that described with referenceto FIG. 9 a and b. However, the mesh has a perimeter member 80 havingangled sides. Further it may have transverse members arranged only toextend towards the perimeter of the mesh, rather than all being acrossthe diameter of the mesh. This provides a more uniform structure. Morespecifically, referring to FIG. 9 d the mesh has a transverse member 84extending along its axis of symmetry, a transverse member 86 bisectingthe axis of symmetry, and four further transverse members 88 extendingfrom the axis of symmetry to the perimeter of the mesh 90.

In addition to the pores provided by the combination of filaments 26which form the strands 22, pores can be provided by rings ofpolypropylene positioned at the intersection of the circumferential andtransverse members.

Alternatively the pores may be formed by the spacing of the transversemembers, such that pores of a size 50-200 μm suitable for enablingtissue ingrowth exist between the transverse members.

To secure the mesh to a suitable location in the body a number ofmethods can be used. The tackiness of the absorbable coating may holdthe mesh suitably until it is secured by tissue ingrowth.

Alternatively the surgical implant can have capsules 100 (not shown) ofbiocompatible glue for securing the mesh 20 in place. In this example,six capsules 100 comprising spheres having a diameter of 4 mm and madefrom a rapidly absorbable material are provided around the perimeter ofthe mesh 20. On placement in the body, the capsules 100 dissolve andrelease a biocompatible glue contained within to secure the mesh 20 inplace.

Referring to FIG. 10, a tool 200 for inserting one of the meshesdescribed (usually without an absorbable coating 32) comprises twochannels 202, 204. The channels 202, 204 are semi-circular incross-section and the channel 202 has a diameter slightly smaller thanthe diameter of channel 204. The channels are interconnected such thatthe channel 202 can be rotated inside the channel 204. In use, the mesh20 is rolled up and placed in the space formed by the channels 202, 204in a first position in which the open sides of the channels face oneanother to form a housing or tube. After insertion into the desiredlocation, channel 204 is rotated inside the channel 202 to release themesh 20.

Referring to FIG. 11, an alternative tool 210 for inserting one of themeshes described comprises an elongate housing 212 around which the meshis rolled and secured. The tool 210 has means for trapping an edge ofthe mesh 20 to secure it on the housing of the tool 212, such as agroove 214. In use, once the mesh 20 has been rolled around the housingof the tool 210 it may be secured by a removable clip or other suchretaining means (not shown). After insertion of the tool 210 into thedesired location, the mesh 20 is released and the tool 210 is rotated tounfurl the mesh 20.

Referring to FIG. 12, another alternative tool 220 for inserting one ofthe meshes described above in the body comprises two arms 222 pivotallyinterconnected by a pivot 224. One end of each arm 226 has means forbeing releasably attached to the mesh 20. The other end of each arm 228is operable to move the ends that may be attached to the mesh 20 towardor away from one another by rotation around the pivot 224. When the endsof the arms 226,228 to which the mesh 20 can be attached are moved to aposition in which they are close to one another, the tool 220 issubstantially elongate. Furthermore, the mesh 20 is radially confined bythe arms. Once the mesh 20 has been inserted into position, the arms226,228 can be manipulated to move the ends to which the mesh 20 can beattached apart to unfurl the mesh 20 in its intended position.

Referring to FIG. 13, another tool 230 for inserting one of the meshesdescribed above in its desired location comprises an elongate housing232 having a number of pairs of holes 234 spaced along its length (inthis example three pairs) at the distal end of the tool 230. The housing232 is hollow and contains a number (in this case three) of pairs ofwires 236, made from polypropylene for example, which extend along thelength of the housing 232 and out through the pairs of holes 234. Thewires 236 also protrude from the proximal end of the housing such thatthey can be pushed and pulled in and out of the housing 232. The ends ofthe wires 236 that protrude from the holes 234 have means for releasablyattaching to points near the perimeter of the mesh 20.

In use, the wires 236 are attached to the mesh 20 and retracted bypulling them back through the housing 30 such that the mesh 20 isradially confined close to the housing 232. Once the tool 230 has beeninserted into the intended position, the wires 236 are pushed into thehousing 232 and consequently out through the holes 234 to urge the mesh20 away from the housing 232. Thus, the mesh 20 can be unfurled in itsdesired location in the body.

Referring once again to FIG. 5 in order to repair a urethracoeleprolapse i.e. a defect in the area A of FIG. 5, the surgeon firstlocates the defect by examining the patient in the conventional manner.The extent of the defect can then be ascertained and, if necessary, asuitable template used to estimate the shape and dimensions of apreferred surgical implant to repair the defect. A suitably shapedsurgical implant can then be selected.

The meshes described above are, in this example, supplied in a singlesize. After examination of the patient and estimation of the desireddimensions of the preferred mesh, the surgeon cuts the mesh to thepreferred size.

Where the mesh comprises a circumferential member 70 the cut made in themesh is through the transverse members 76 just outward of thecircumferential member 70 corresponding most closely with the preferredsize of mesh. Thus, regardless of the size to which the mesh is to becut, a circumferential member 70 defines the perimeter of the mesh, andthe perimeter of the mesh is substantially smooth. This desirablyreduces the likelihood of infection or edge erosion once the mesh isinserted in the body.

The surgeon then attaches the mesh to or inserts the mesh with one ofthe insertion tools described herein. For example, the mesh is rolled upand placed within the insertion tool 200 illustrated in FIG. 10, wrappedaround the insertion tool 210 illustrated in FIG. 11, attached to theends of the arms 222 of the insertion tool 220 illustrated in FIG. 12 orattached to the ends of the wires 236 of the insertion tool 230illustrated in FIG. 13.

An incision 9 is then made in the vaginal wall 12 at the forward mostportion of the vaginal wall 12 adjacent the opening of the vaginalcavity. A cutting implement (not illustrated), such as scissors or aspecialised cutting tool, is/are then inserted through the incision 9into the area A, i.e. the lower portion of the anterior vaginal wall 12.Using the cutting implement, a cut is made in the area A parallel withthe surface of the vaginal wall 12. In other words, a space is opened upin the vaginal wall 12 over the area of the defect in the vaginal wall12. The cutting implement is then withdrawn and the mesh 20 is insertedin the space defined by the cut.

Where the insertion tool 200 illustrated in FIG. 10 is used, the tool200 is inserted into the area A and the channel 202 rotated to aposition within the channel 204 to release the mesh 20. The insertiontool 200 can then be retracted and the mesh unfurls due to its inherentresilience or flat memory. Should it be required to help the mesh 20 tounfurl, or slightly re-position the mesh 20 defect 2, an elongate tool(not shown) may be inserted through the incision 9 or needles may beintroduced directly through the vaginal wall 12 to manipulate the mesh20. This procedure can be viewed laproscopically through the incision 9if desired.

Where the insertion tool 210 illustrated in FIG. 11 is used, it isdesirable for the insertion tool 210 to be inserted to one side of thespace defined by the cut. The mesh 20 is then released and a needleinserted through the vaginal wall to hold the released edge of the mesh20 in position. The tool 210 is then rolled across the space defined bythe cut in an arc having a centre of rotation around the incision 9.Thus, the mesh 20 is unfurled, but no significant movement is requiredaround the incision 9.

Where the insertion tool 220 illustrated in FIG. 12 is used, theinsertion tool 220 is simply inserted through the incision 9 and openedto expand the mesh 20 into its desired location. The mesh 20 is releasedfrom the insertion tool 220 which can then be closed and withdrawnthrough the incision 9.

Finally, where the insertion tool 250 illustrated in FIG. 13 is used,the mesh 20 is retracted by withdrawing the wires 236 through theirholes 234 and the mesh is inserted through the incision 9. Once theinsertion tool 230 has been inserted into its desired location, thewires 236 are urged forward and out through the holes 234 to expand themesh in its intended position. The wires 236 can then be released fromthe mesh 20, withdrawn into the housing 232 and the tool 230 withdrawnthrough the incision 9.

Once the mesh 20 is in place, the incision may be closed.

However, it can be desirable to secure the 20 in place, rather than relyon the mesh 20 remaining in its desired location of its own accord. Inone example, sutures are therefore be placed either laproscopicallythrough the incision 9 or directly through the vaginal wall 12 to holdthe mesh 20 in place. In another example, glue capsules provided on themesh 20 dissolve to secure the mesh 20 to the tissue surrounding thespace defined by the cut, or such capsules may be punctured by needlesinserted directly through the vaginal wall 12.

The surgical implant described herein is advantageous over the meshes ofthe prior art in several ways.

In particular the mesh of the present invention includes smoother edges,the polyester material of the present invention being softer thanpolypropylene. Further, the filaments of the present invention arenarrower in diameter enabling them to be more pliable than the strandsof the meshes of the prior art. This causes the edge or edges of themesh of the present invention to have fewer jagged edges and thus besmoother that the edges of meshes or the prior art.

In addition encasement of the mesh in an absorbable coating furtherprotects the tissue both during placement and for a period of time afterplacement of the surgical implant.

Dual Phase Technology™ such as encasement in an absorbable coating or asotherwise discussed herein provides the implant with good handlingcharacteristics, further it enables the implant to be more easily cut.As described above an absorbable coating may protect the tissues aroundwhere the implant is to be located both during placement and for aperiod of time following placement of the implant in the tissue.

Dual Phase Technology™ may also provide the implant with memory. Thismemory may allow the implant to be more easily placed flat on thetissue. Further the dual phase technology such as an absorbable coatingmay provide the implant with mild adhesive properties or tackiness whichwould aid both the locating and securing of the implant in the tissue.

The surgical implant described herein thus allows tension free repair ofhernias, particular vaginal prolopse, with minimum pain. This allows theprocedure to be performed under local anaesthetic in an out patient oroffice setting.

Whilst the above embodiments of the invention have been described withreference to vaginal prolapse, the mesh and surgical tools may equallybe used to repair any bodily hernia. Furthermore, whilst the aboveprocedure has been described in relation to a urethrocoele prolapse,prolapse in other parts of the vaginal wall 12 can be treated throughincisions elsewhere in the vaginal wall, or other bodily hernias throughsuitable incisions in the appropriate tissue.

1. A surgical implant adapted to treat a prolapse in a patient, thesurgical implant comprising: a knitted mesh having a mass density ofless than 25 g/m², wherein the knitted mesh comprises: at least onebiocompatible monofilament formed from polypropylene and having adiameter of from about 0.02 mm to 0.15 mm; and openings formed betweenthe at least one monofilament to allow blood to pass through the knittedmesh or to allow fibroblast throughgrowth, wherein the openings includeat least one of pores having a diameter of from about 50 μm to 200 μmand major spaces having a width of from about 1 mm to 10 mm, wherein theimplant is non-absorbable and is configured to be implanted in a regionof the prolapse, wherein the prolapse is selected from the groupconsisting of urethrocoele prolapse, cystocoele prolapse, vaultprolapse, uterine prolapse, enterocoele prolapse, and rectocoeleprolapse, and wherein the knitted mesh is configured to be secured inplace to treat the prolapse.
 2. The implant of claim 1, wherein the atleast one monofilament has a diameter of from about 0.08 mm to 0.1 mm.3. The implant of claim 1, wherein the implant has a width of from about1 cm to 10 cm.
 4. The implant of claim 1, wherein the knitted mesh is awarp knitted mesh.
 5. The implant of claim 1, wherein the openingsinclude major spaces formed by spaced apart strands.
 6. The implant ofclaim 5, wherein the openings further include pores formed within thestrands.
 7. The implant of claim 5, wherein the strands have a diameterof from about 150 μm to 600 μm.
 8. A surgical implant adapted to treat aprolapse in a patient, the surgical implant comprising: a knitted meshhaving a mass density of less than 25 g/m², wherein the mesh comprises:at least one biocompatible polypropylene filament and having a diameterof from about 0.02 mm to 0.15 mm; and openings formed in the knittedmesh to allow blood to pass through the knitted mesh or allow fibroblastthroughgrowth, wherein the openings include at least one of pores havinga diameter of from about 50 μm to 200 μm and major spaces having a widthof from about 1 mm to 10 mm, wherein the implant is configured to beimplanted in a region of the prolapse, wherein the prolapse is selectedfrom the group consisting of urethrocoele prolapse, cystocoele prolapse,vault prolapse, uterine prolapse, enterocoele prolapse, and rectocoeleprolapse, and wherein the knitted mesh is configured to be secured inplace to treat the prolapse.
 9. The implant of claim 8, wherein the atleast one filament is a monofilament.
 10. The implant of claim 8,wherein the implant is non-absorbable.
 11. The implant of claim 8,wherein the at least one filament forms strands and wherein the poresare formed between the at least one filament and within the strands. 12.The implant of claim 11, wherein the implant is configured to beattached to a vaginal wall.
 13. A method for treating a vaginal prolapsein a patient, the method comprising: accessing the vaginal prolapse,wherein the prolapse is selected from the group consisting ofurethrocoele prolapse, cystocoele prolapse, vault prolapse, uterineprolapse, enterocoele prolapse, and rectocoele prolapse; inserting animplant into a patient, the implant comprising: a knitted mesh having amass density of less than 25 g/m², wherein the mesh comprises: at leastone biocompatible monofilament formed from polypropylene and having adiameter of from about 0.02 mm to 0.15 mm; and openings formed in themesh to allow at least one of blood to pass through the mesh andfibroblast throughgrowth, wherein the openings formed between themonofilaments include at least one of pores having a diameter of fromabout 50 μm to 200 μm and major spaces having a width of from about 1 mmto 10 mm; and securing the knitted mesh in place such that the implantsupports the pelvic floor of the patient.
 14. The method of claim 13,wherein securing the knitted mesh in place includes securing the knittedmesh in place with sutures.
 15. The method of claim 13, whereininserting the implant includes inserting a non-absorbable implant. 16.The method of claim 13, wherein the knitted mesh is a warp knitted mesh.17. The method of claim 13, wherein securing the knitted mesh in placecomprises securing the knitted mesh in place such that the implantsupports a vaginal wall of the patient.
 18. The method of claim 13,wherein accessing the vaginal prolapse comprises accessing the vaginalprolapse through a minimally invasive surgical procedure.
 19. The methodclaim 13, wherein the at least one monofilament forms strands andwherein the knitted mesh comprise pores formed within the strands andmajor spaces formed between adjacent strands.
 20. The method of claim19, wherein the strands have a diameter of from about 150 μm to 600 μm.